String of cash

A string of cash coins (Traditional Chinese: 貫, 索, 緡, 繦, 鏹, 吊, 串, 弔, 錢貫, 貫錢; Vietnamese: Xâu tiền; French: Ligature de sapèques) refers to a historical Chinese, Japanese, Korean, Ryukyuan, and Vietnamese currency unit that was used as a superunit of the Chinese cash, Japanese mon, Korean mun, Ryukyuan mon, and Vietnamese văn currencies. The square hole in the middle of cash coins served to allow for them to be strung together in strings. The term would later also be used on banknotes and served there as a superunit of wén (文). Usually 1000 wén, but the number could be substantially different depending on the time and place.

Prior to the Song dynasty strings of cash coins were called guàn (貫), suǒ (索), or mín (緡), while during the Ming and Qing dynasties they were called chuàn (串) or diào (吊). In Japan and Vietnam the term 貫 would continue to be used until the abolition of cash coins in those respective countries.

During the Qing dynasty a string of 1000 cash coins valued at 1 tael of silver, although variants of regional standards as low as 500 cash coins per string also existed. A total of 1000 coins strung together were referred to as a chuàn (串) or diào (吊) and were accepted by traders and merchants per string because counting the individual coins would take too much time. The coins were made up of bronze to protect China's economy. Because the strings were often accepted without being checked for damaged coins and coins of inferior quality and copper alloys, these strings would eventually be accepted based on their nominal value rather than their weight; this system is comparable to that of a fiat currency.